Count Instances Of The Class Using C#

Introduction

 

In this blog, I am going to explain how to find the number of objects or instances that are created of a class, using C# . Thus, In my blog, I am going to solve this scenario in two ways.

• Without using the inbuilt functionality in C#
• Using the inbuilt functionality in C#

In both the cases, we can use the constructor.

Constructor 

 

Constructor is used to initialize an object (instance) of a class and it has the same name as the class name. Constructor is a like a method without any return type.

 

Destructor

 

Destructor in C# is a special method of a class, which will invoke automatically, when an instance of the class is destroyed.

 

Check the following example to find the number of instances created in a class, using C#.

 

Without using Inbuilt functionality in C#

 

Code

 

The following code will help to find the number of instances created in a class, using C#. In this example, we created 4 objects in a test class. Thus, before the execution of a constructor, we need to add static int count = 0. In each object initialization time of a class, the constructor will execute once. Thus, we will get the number of objects created by a class in C#. 

using System;

namespace data
{
    public class test
    {
        public static int count = 0;
        public test()
        {
            count = count + 1;
        }
    }

    public class Program
    {
        public static void Main()
        {
            test obj1 = new test();
            test obj2 = new test();
            test obj3 = new test();
            test obj4 = new test();
            Console.WriteLine(data.test.count);
        }
    }
}

Output 4

 

Demo : Count the instance of a class in C#

 

Using Inbuilt functionality in C#

 

Interlocked

 

Interlocked helps in the threaded programs and it provides automatic operations for the variables that are shared by the multiple threads.

 

Code

using System;
using System.Threading;

namespace data
{
    public class test
    {
        public static int count = 0;
        public test()
        {
            Interlocked.Increment(ref count);
        }

        ~test()
        {
            Interlocked.Decrement(ref count);
        }
    }

    public class Program
    {
        public static void Main()
        {
            test obj1 = new test();
            test obj2 = new test();
            test obj3 = new test();
            Console.WriteLine(data.test.count);
        }
    }
}

Output 3

 

Demo : Count instances of the class using Inbuilt functionality in C#

 

Reference

• Interlocked Class
• Tech Blog

Summary

We learned how to find the number of instances created in a class, using C#. I hope this article is useful for all .NET beginners.